Currently, light-emitting diodes (LED) are widely applied for its good light quality and high luminous efficiency. Generally, conventional full-color LED display devices include red, green, and blue LED chips cooperating together to widen color gamut and enhance the color rendering. The red, green, and blue LED chips can respectively emit red, green, and blue colored lights. Therefore, the full-color LED display devices can produce a full-color light by directly emitting the single red, green, or blue colored lights or superposing at least two of the red, green, blue colored lights to display the colored information.